Torricelli Evandlzhlista (Torricelli Evangelista)

(1608-1647)
Born October 15, 1608 in Faenza. In 1627 came to Rome, where he studied mathematics under the guidance of B. Castelli, a friend and pupil of Galileo Galilei. Impressed by the works of Galileo on the motion write your own essay on the same subject, entitled A Treatise on the motion (Trattato del moto, 1640). In 1641 he moved to Arcetri, where he became a disciple and secretary of Galilee, and later his successor at the department of mathematics and philosophy, University of Florence.
Building on research of Galileo, Torricelli in 1643 showed that air has weight and that the pump can not pull the water to a height of more than 10 m. Torricelli, together with V. Viviani (1622-1703) posed the following experience. The glass tube length of approximately. 1 m, sealed at one end, was filled with mercury. The opening of the tube was closed with his finger and dropped the open end down into a wide vessel with mercury. It turns out that if you now take a finger, the column of mercury in the tube falls to a height of approximately. 76 cm, and above the surface of mercury in the tube is formed sparse space (Torricellian vacuum). The height of the mercury column varied depending on weather conditions, and Torricelli concluded that this height is measured air pressure (atmospheric pressure). Constructed of the instrument was essentially the first barometer, and many modern barometers of their design do not differ much from the tube, Torricelli. In 1641 Torricelli law formulated leaking fluid from the holes in the wall of an open container and derived a formula for determining the rate of outflow (equation Torricelli). Torricelli died in Florence on Sept. 25, 1647.